/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
 * Copyright 2003-2007 Jive Software.
 *
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.smackx;

import org.jivesoftware.smack.util.StringUtils;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

/**
 * Represents a field of a form. The field could be used to represent a question
 * to complete, a completed question or a data returned from a search. The exact
 * interpretation of the field depends on the context where the field is used.
 * 
 * @author Gaston Dombiak
 */
public class FormField {

	public static final String TYPE_BOOLEAN = "boolean";
	public static final String TYPE_FIXED = "fixed";
	public static final String TYPE_HIDDEN = "hidden";
	public static final String TYPE_JID_MULTI = "jid-multi";
	public static final String TYPE_JID_SINGLE = "jid-single";
	public static final String TYPE_LIST_MULTI = "list-multi";
	public static final String TYPE_LIST_SINGLE = "list-single";
	public static final String TYPE_TEXT_MULTI = "text-multi";
	public static final String TYPE_TEXT_PRIVATE = "text-private";
	public static final String TYPE_TEXT_SINGLE = "text-single";

	private String description;
	private boolean required = false;
	private String label;
	private String variable;
	private String type;
	private final List<Option> options = new ArrayList<Option>();
	private final List<String> values = new ArrayList<String>();

	/**
	 * Creates a new FormField with the variable name that uniquely identifies
	 * the field in the context of the form.
	 * 
	 * @param variable
	 *            the variable name of the question.
	 */
	public FormField(String variable) {
		this.variable = variable;
	}

	/**
	 * Creates a new FormField of type FIXED. The fields of type FIXED do not
	 * define a variable name.
	 */
	public FormField() {
		this.type = FormField.TYPE_FIXED;
	}

	/**
	 * Returns a description that provides extra clarification about the
	 * question. This information could be presented to the user either in
	 * tool-tip, help button, or as a section of text before the question.
	 * <p>
	 * <p/>
	 * If the question is of type FIXED then the description should remain
	 * empty.
	 * 
	 * @return description that provides extra clarification about the question.
	 */
	public String getDescription() {
		return description;
	}

	/**
	 * Returns the label of the question which should give enough information to
	 * the user to fill out the form.
	 * 
	 * @return label of the question.
	 */
	public String getLabel() {
		return label;
	}

	/**
	 * Returns an Iterator for the available options that the user has in order
	 * to answer the question.
	 * 
	 * @return Iterator for the available options.
	 */
	public Iterator<Option> getOptions() {
		synchronized (options) {
			return Collections.unmodifiableList(new ArrayList<Option>(options))
					.iterator();
		}
	}

	/**
	 * Returns true if the question must be answered in order to complete the
	 * questionnaire.
	 * 
	 * @return true if the question must be answered in order to complete the
	 *         questionnaire.
	 */
	public boolean isRequired() {
		return required;
	}

	/**
	 * Returns an indicative of the format for the data to answer. Valid formats
	 * are:
	 * <p/>
	 * <ul>
	 * <li>text-single -> single line or word of text
	 * <li>text-private -> instead of showing the user what they typed, you show
	 * ***** to protect it
	 * <li>text-multi -> multiple lines of text entry
	 * <li>list-single -> given a list of choices, pick one
	 * <li>list-multi -> given a list of choices, pick one or more
	 * <li>boolean -> 0 or 1, true or false, yes or no. Default value is 0
	 * <li>fixed -> fixed for putting in text to show sections, or just
	 * advertise your web site in the middle of the form
	 * <li>hidden -> is not given to the user at all, but returned with the
	 * questionnaire
	 * <li>jid-single -> Jabber ID - choosing a JID from your roster, and
	 * entering one based on the rules for a JID.
	 * <li>jid-multi -> multiple entries for JIDs
	 * </ul>
	 * 
	 * @return format for the data to answer.
	 */
	public String getType() {
		return type;
	}

	/**
	 * Returns an Iterator for the default values of the question if the
	 * question is part of a form to fill out. Otherwise, returns an Iterator
	 * for the answered values of the question.
	 * 
	 * @return an Iterator for the default values or answered values of the
	 *         question.
	 */
	public Iterator<String> getValues() {
		synchronized (values) {
			return Collections.unmodifiableList(new ArrayList<String>(values))
					.iterator();
		}
	}

	/**
	 * Returns the variable name that the question is filling out.
	 * 
	 * @return the variable name of the question.
	 */
	public String getVariable() {
		return variable;
	}

	/**
	 * Sets a description that provides extra clarification about the question.
	 * This information could be presented to the user either in tool-tip, help
	 * button, or as a section of text before the question.
	 * <p>
	 * <p/>
	 * If the question is of type FIXED then the description should remain
	 * empty.
	 * 
	 * @param description
	 *            provides extra clarification about the question.
	 */
	public void setDescription(String description) {
		this.description = description;
	}

	/**
	 * Sets the label of the question which should give enough information to
	 * the user to fill out the form.
	 * 
	 * @param label
	 *            the label of the question.
	 */
	public void setLabel(String label) {
		this.label = label;
	}

	/**
	 * Sets if the question must be answered in order to complete the
	 * questionnaire.
	 * 
	 * @param required
	 *            if the question must be answered in order to complete the
	 *            questionnaire.
	 */
	public void setRequired(boolean required) {
		this.required = required;
	}

	/**
	 * Sets an indicative of the format for the data to answer. Valid formats
	 * are:
	 * <p/>
	 * <ul>
	 * <li>text-single -> single line or word of text
	 * <li>text-private -> instead of showing the user what they typed, you show
	 * ***** to protect it
	 * <li>text-multi -> multiple lines of text entry
	 * <li>list-single -> given a list of choices, pick one
	 * <li>list-multi -> given a list of choices, pick one or more
	 * <li>boolean -> 0 or 1, true or false, yes or no. Default value is 0
	 * <li>fixed -> fixed for putting in text to show sections, or just
	 * advertise your web site in the middle of the form
	 * <li>hidden -> is not given to the user at all, but returned with the
	 * questionnaire
	 * <li>jid-single -> Jabber ID - choosing a JID from your roster, and
	 * entering one based on the rules for a JID.
	 * <li>jid-multi -> multiple entries for JIDs
	 * </ul>
	 * 
	 * @param type
	 *            an indicative of the format for the data to answer.
	 */
	public void setType(String type) {
		this.type = type;
	}

	/**
	 * Adds a default value to the question if the question is part of a form to
	 * fill out. Otherwise, adds an answered value to the question.
	 * 
	 * @param value
	 *            a default value or an answered value of the question.
	 */
	public void addValue(String value) {
		synchronized (values) {
			values.add(value);
		}
	}

	/**
	 * Adds a default values to the question if the question is part of a form
	 * to fill out. Otherwise, adds an answered values to the question.
	 * 
	 * @param newValues
	 *            default values or an answered values of the question.
	 */
	public void addValues(List<String> newValues) {
		synchronized (values) {
			values.addAll(newValues);
		}
	}

	/**
	 * Removes all the values of the field.
	 */
	protected void resetValues() {
		synchronized (values) {
			values.removeAll(new ArrayList<String>(values));
		}
	}

	/**
	 * Adss an available options to the question that the user has in order to
	 * answer the question.
	 * 
	 * @param option
	 *            a new available option for the question.
	 */
	public void addOption(Option option) {
		synchronized (options) {
			options.add(option);
		}
	}

	public String toXML() {
		StringBuilder buf = new StringBuilder();
		buf.append("<field");
		// Add attributes
		if (getLabel() != null) {
			buf.append(" label=\"").append(getLabel()).append("\"");
		}
		if (getVariable() != null) {
			buf.append(" var=\"").append(getVariable()).append("\"");
		}
		if (getType() != null) {
			buf.append(" type=\"").append(getType()).append("\"");
		}
		buf.append(">");
		// Add elements
		if (getDescription() != null) {
			buf.append("<desc>").append(getDescription()).append("</desc>");
		}
		if (isRequired()) {
			buf.append("<required/>");
		}
		// Loop through all the values and append them to the string buffer
		for (Iterator<String> i = getValues(); i.hasNext();) {
			buf.append("<value>").append(i.next()).append("</value>");
		}
		// Loop through all the values and append them to the string buffer
		for (Iterator i = getOptions(); i.hasNext();) {
			buf.append(((Option) i.next()).toXML());
		}
		buf.append("</field>");
		return buf.toString();
	}

	/**
	 * Represents the available option of a given FormField.
	 * 
	 * @author Gaston Dombiak
	 */
	public static class Option {

		private String label;
		private String value;

		public Option(String value) {
			this.value = value;
		}

		public Option(String label, String value) {
			this.label = label;
			this.value = value;
		}

		/**
		 * Returns the label that represents the option.
		 * 
		 * @return the label that represents the option.
		 */
		public String getLabel() {
			return label;
		}

		/**
		 * Returns the value of the option.
		 * 
		 * @return the value of the option.
		 */
		public String getValue() {
			return value;
		}

		public String toString() {
			return getLabel();
		}

		public String toXML() {
			StringBuilder buf = new StringBuilder();
			buf.append("<option");
			// Add attribute
			if (getLabel() != null) {
				buf.append(" label=\"").append(getLabel()).append("\"");
			}
			buf.append(">");
			// Add element
			buf.append("<value>").append(StringUtils.escapeForXML(getValue()))
					.append("</value>");

			buf.append("</option>");
			return buf.toString();
		}
	}
}
